That is exactly how he told it in the OP, and he has tried to weasel his way out of it ever since, because it was pointed out what an utter **** he was.
Quote from the OP..... "the traffic was zip merging for some reason"
Just think Kev, before you got to the junction, the traffic was zip merging, and all roads would have been flowing. along comes Mr Kev in his big get out of my way truck, with the noisy horn, and suddenly the traffic on the slip road has to stop, back up onto the roundabout, all the approaches to the roundabout have to stop. The traffic on the motorway was flowing, but now because Mr Kev has insisted on his right of way, with his big get out of my way truck with the noisy horn, traffic behind him finds itself approaching a stationary queue of traffic trying to join. Because the joining traffic is stationary, the only way it is going to merge into lane 1 is if someone stops (and there are some considerate driver who will allow other motorists to join the motorway) so now lane 1 is stationary too.
Putting your ego awayslower back', 'hand and Yes, I often say that my travels are virtually hbuttle free, but I must admit...
Proud?